Ok, so I've always been a really scrawny guy until I started working out. I've come a long way but I think at this point, it's time for me to start bulking. I did a sort of 'test run' to see if I could even bulk at a decent rate since my metabolism is so high. In two weeks, I gained 7 pounds. BFC went from ~6% to ~8%. Now that I know I can bulk, I need guidance as I've never done it.

I went from 163lbs -> 170lbs in two weeks. Is this too much and at what point do I stop bulking, cut calories and slim out? I'm going on vacation in May and want to be back down to ~6/7BFC by then.

The main thing so far that I've noticed as far as body difference with bulking is that my abs aren't as defined. This being the case, I assume in not too long, my abs will be just about gone. Should I still do my ab workouts or should I wait until I slim out?

Definitely keep working them. Bulking is when you should be working out hard. You know you're gaining weight because you have a surplus of calories so this is the time to stimulate as much growth as possible.

One thing you need to know is that your weight fluctuates a lot. I can easily weigh in during the morning and again later during the day with a 4-7lb difference. It's almost gauranteed that you did not experience a 7lb change in body tissue. It sounds more like you've weighed yourself at different times in the day, the heavier being after a big meal, perhaps later in the day when you're bloated, the smaller of the two numbers being from a morning weigh-in. Also factor in what you're wearing when you weigh yourself.
Don't worry or change anything. In the future, check your weight on a daily basis, and then look at the average increase in weight over the period of weeks and months.

They are notoriously unreliable. The only really reliable methods for body fat percentage are a DEXA scan or hydrostatic weighing. I would track your weight, get some measurements of body parts you find important (biceps, forearms, quads, chest, calves are what I measure) and keep track of your lifts. Those are your best friends for tracking progress.

i recommend saving your semen. Full of extra calories and proteins. If the thought of eating it grosses you out/makes you feel gay/don't like the taste then add it to a shake and you'll never know it was there :)

Could be a bit weird explaining that to your family if they see you doing that though...

Ab definition is going to vary during a bulk based on when you're checking yourself out. Did you just drink a ton of milk and/or sodium? Had a big meal? My ab definition is semi visible after a good work but practically gone after my big morning meal.

you probably don't need that many shakes & bars, add up how much protein you're getting from your food every day. 1g protein per pound of bodyweight is more than enough, so for you, 170g is plenty. maybe save you some money.

though nothing wrong with extra calories/protein when bulking up, but too much extra isn't always necessary

You will gain some fat as you bulk but it's just covering your muscle mass. Bulk for a while then cut back down. I like to bulk during winter and cut during summer to take advantage of the natural benefits of the weather.